Catalyst for the synthesis of alkyl mercaptan and process for its preparation

Abstract

A catalyst may include a support and from 5 to 20 wt.-% of a promoter, based on the total weight of the catalyst, wherein the support may include titanium dioxide, zirconium dioxide, and/or a mixture thereof, and the promoter may be an alkali metal oxide. Processes for preparing such catalysts may include impregnating a support of titanium dioxide and/or zirconium dioxide with an aqueous solution including a preferably soluble alkali compound and calcining. Alkyl mercaptans may be prepared in the presence of such catalysts or catalysts obtained by such processes.

The invention claimed is: 
     
       1. A process for preparing an alkyl mercaptan, the process comprising:
 reacting an alkyl alcohol with hydrogen sulfide in the presence of a catalyst comprising: 
 a support; and 
 5 to 20 wt. % of cesium oxide, based on total catalyst weight, wherein the support consists of titanium dioxide and/or zirconium dioxide, and at least a part of the support has a tetragonal phase. 
 
     
     
       2. The process of  claim 1 , wherein the catalyst is a full catalyst. 
     
     
       3. The process of  claim 1 , wherein the catalyst is a core-shell catalyst. 
     
     
       4. The process of  claim 1 , wherein the catalyst is obtained by a process comprising:
 (a) impregnating a support consisting of titanium dioxide and/or zirconium dioxide with an aqueous solution comprising a soluble cesium compound, to obtain an impregnated support; 
 (b) drying the impregnated support, to obtain a dried impregnated support; and 
 (c) calcining the dried impregnated support to provide the catalyst. 
 
     
     
       5. The process of  claim 4 , wherein the impregnating (a), the drying (b), and the calcining (c) are repeated at least once. 
     
     
       6. The process of  claim 4 , wherein the process to obtain the catalyst further comprises:
 (d1) shaping the catalyst obtained from the calcining (c) to give a full catalyst. 
 
     
     
       7. The process of  claim 4 , wherein the process to obtain the catalyst further comprises:
 d2) applying the catalyst obtained from the calcining (c) to a core to provide a core-shell catalyst. 
 
     
     
       8. The process of  claim 1 , wherein the alkyl alcohol to be reacted is methanol and the alkyl mercaptan to be prepared is methyl mercaptan.